In a decision posted Monday, the Colorado Supreme Court says that a lower court was right in selecting a map that made many districts more competitive between Democrats and Republicans. Lawyers aligned with the GOP had argued that it was more important to preserve existing congressional boundaries. Republicans currently hold a 4-3 majority in the U.S. House delegation.

The Colorado Supreme Court says it agrees that competitive districts can produce lawmakers who work harder because they’re not politically safe. The court upheld the map in December but posted its explanation Monday.

Dissenting Justice Allison Eid wrote that big changes to congressional lines were “astonishing” because the state didn’t gain or lose seats.